A typical suspended ceiling arrangement comprises a plurality of rectangular ceiling tiles which are supported by a supporting structure which often is comprised of inverted T-profiles forming a grid. The supporting structure, in turn, is preferably mounted in a main ceiling of a room or an accommodation in which the suspended ceiling is to be installed.
Moreover, the undersides of the grid of T-profiles may be exposed or concealed. Often, parts of the grid are exposed, being visible from below the suspended ceiling, while other parts are concealed. One way to conceal the undersides of the T-profiles, thereby increasing the aesthetical characteristics of the suspended ceiling, is to arrange parts of the T-profile within kerfs of the ceiling tile.
Commonly, it is desirable that the ceiling tiles are demountable from the suspended ceiling. In particular, easily demountable ceiling tiles are convenient when a quick access to the plenum space, which is formed between the suspended ceiling and the main ceiling, is required. For instance, this may happen when a wire, a pipe or a heating, ventilation or air-conditioning device placed in the plenum space needs to be maintained or repaired.
Sometimes it is important that the ceiling tiles comprised in the suspended ceiling are securely kept in position in the event of voluntary or involuntary forces being applied to them. These forces may be induced by e.g. an earthquake, a cleaning process the ceiling tiles, a sudden change of air pressure in the room caused by an abruptly opened or closed door, etc.
The suspended ceiling may have sound absorbing as well as sound attenuating properties for improving the sound environment inside as well as outside of the room or accommodation.
EP1260645B1 discloses a ceiling slab comprising a frame, a slab-shaped body made of a sound-damping material and a cover. The slab-shaped body is adapted to the frame and placed in positive contact therein, and the thickness of the frame is greater than the thickness of the slab-shaped body. The cover spans the slab-shaped body at a distance and runs on the upper side of the frame and/or the lower outer side of the frame. The cover may be made of plastic material, e.g. PVC-film, but may also be made of textile material or any other efficient material.
Nevertheless, the ceiling slab according to EP1260645B1 may further be improved concerning acoustic behaviour.